Sen. John KennedyJohn Neely KennedyMORE (R-La.) predicted that his caucus will be able to get enough support to pass the budget because most lawmakers view it as a necessary stepping stone to being able to pass tax reform.

“I think people understand that it’s more about tax reform than the budget, and it’s a necessary step so we can move to tax reform," he said.

Tuesday's vote kicks off roughly two days of debate on the Senate floor and a marathon session — known as a vote-a-rama — before senators can take a final vote on the budget.

The vote-a-rama is expected to start on Thursday and run late into the night, meaning a final vote on the budget is likely to take place on Thursday night or early Friday morning.

The Senate's budget would cut nondefense spending starting in 2019 and result in up to $106 billion by 2027. It would also only cut mandatory spending by $1 billion, compared to the House version’s $203 billion.

It would also allow the Senate GOP's tax plan to add up to $1.5 trillion to the deficit over a decade.